In the field of internal combustion engines it is known to use fuel intake valves and combustion product exhaust valves, the opening/closing of which is controlled by camshafts actuated by a mechanical chain drive.
The chains are components subject to high stress and continuous progressive wear, which often cause sudden breakage of the chain. Chain breakage must be absolutely avoided to preventive irreparable damage to the engine. For this reason, the known drives of the type described above undergo preventive maintenance which requires replacing the chains after a predetermined time of operation regardless of whether the chains themselves have reached the end of their working life or not.
The scheduled replacement of the chains implies inevitable, long machine downtime and high replacement costs.